Field of the Invention
The invention concerns a novel combination of a calcium antagonist and a pyrimidine derivative intended to induce and stimulate hair growth, also a method of treatment using said combination.
An individual has about 100 000 to 150 000 hairs on his head and normally 50 to 100 are lost daily. The number is maintained primarily because a hair has a pilary life cycle comprising formation, growth and fall before being replaced by a new hair appearing from the same follicle.
There are three phases in the pilary cycle: the anagenous, catagenous and telogenous phases.
During the first, anagenous, phase the hair goes through a period of active growth associated with intense metabolic activity in the root.
The second, catagenous, phase is transient and characterized by slowing of mitotic activities. During this phase the hair undergoes involution, the follicle atrophies and its dermal implantation appears increasingly raised.
The final, telogenous, phase corresponds to the follicle's rest period and the hair finally falls out, pushed out by a newly-formed anagenous hair.
This continuous physical renewal process evolves naturally during ageing with the hair becoming finer and the cycles shorter.
Alopecia occurs when this physical renewal process is accelerated or perturbed, ie the growth phases are shortened, the hair goes into the telogenous phase earlier and more hair falls out. Successive growth cycles result in finer and finer, shorter and shorter hair, gradually ending up as unpigmented down. This phenomenon may result in baldness.
"Minoxidil" (6-amino-1,2,-dihydro,l-hydroxy-2-imino-4-piperidinopyrimidine) has already been used in treating hair loss in topical compositions which reduce or end the effects of alopecia, induce and stimulate hair growth and reduce hair loss.
Orally or parenterally administered calcium antagonists are known in the therapy and treatment of cardiovascular ailments.
It has now, surprisingly been discovered that combining calcium antagonists (which in themselves neither induce or stimulate hair growth nor slow hair loss) with certain pyrimidine derivatives produces the surprising effect of improving the induction and stimulation of hair growth and ameliorating the slowing of hair loss.
In particular, the combination begins to act more quickly than these compositions in isolation. Because of the combination, a lower concentration of the pyrimidine derivative can be employed.
The efficacity or speed of action of a composition for the treatment of alopecia can be especially well determined using a trichogram and in particular a phototrichogram which, inter alia, allows the percentage of hair in the anagenous phase to be determined with respect to the hair in the telogenous phase.
In particular, a combination according to the invention will increase this percentage compared with that when the compositions are used separately.
One object of the invention is to provide a combination of a calcium antagonist and a pyrimidine derivative intended to induce or stimulate hair growth and reduce hair loss.
Another object of the invention is to provide a cosmetic and/or pharmaceutical composition comprising this combination.
A further object of the invention is to provide a device having several compartments containing said combination.
Further objects of the invention will become apparent from the following description and examples.